1. Field of the Disclosure
The present disclosure is generally directed to children's car seats, and more particularly to a head rest adjustment mechanism and lock for same.
2. Description of Related Art
Child car seats are well known in the art. Many have a height adjustable head rest on the upper end of the seat back. There are myriad different adjustment and release mechanisms that are employed on such car seats. For example, a head rest adjustment mechanism is described in U.S. Pat. No. 7,232,185 owned by Graco Children's Products Inc. (Graco), the assignee of the present disclosure. In the '185 patent, the head rest locks into selected ones of a number of optional notches in rails extending vertically along the seat back of the seat. When an actuator is pressed, a locking element is retracted, allowing spring fingers to flex out of the holes and allow for sliding vertical adjustment of the head rest.
Because the flex fingers must be bent, the locking elements that engage with the slots or holes in the rails have a generous lead in/lead out. Also, the flex fingers are not positively locked or blocked while in the engaged or locked position. The flex fingers thus can flex and unlock when the car seat experiences heavy, sudden loads or acceleration, such as during a most severe crash. Thus, it is possible that the flex fingers do not remain locked during such an event. This might allow the head rest to move up or downward during the crash event, even though the actuator has not been pressed or actuated.
In another example, U.S. Pat. No. 6,623,074 describes a method for locking and unlocking a head rest adjustment mechanism. The disclosed device has a cam mechanism to disengage a locking rod from notch features provided in the back side of the shell, which is returned with a spring (see FIG. 1 of the '074 patent). The '074 patent also does not disclose providing any type of blocking feature for the locking elements while in the locked or engaged position.
A number of other patent publications disclose various car seat head rest and adjustment features and components, such as international publication no. WO2010075531 entitled “Child Safety Seat with Height Adjustable Harness” (Graco); U.S. Pat. No. 7,862,117 entitled “Head Rest and Harness Adjustment for Child Car Seat” (Wonderland Nursery Goods); and U.S. Pat. No. 7,232,185 entitled “Adjustable Head Rest for Child Car Seat” (Graco). These publications also do not disclose any type of blocking feature on the height adjustable head rests for the locking elements when in the locked or engaged position.